The following patents are hereby incorporated by reference:
U.S. Pat. No. 3,120,198 to Reid; PA1 U.S. Pat. No. 3,148,635 to Reid; PA1 U.S. Pat. No. 3,427,783 to Reid; and PA1 U.S. Pat. No. 5,247,782 to Rejsa.
The invention relates generally to dough cutting and packing devices. In particular, the present invention is a universal dough cutting and packing apparatus having a mechanism capable of transferring different size dough products to corresponding containers at a high rate of speed without the need for a separate cutting and packing device and without retooling manufacturing equipment prior to processing a different sized dough product.
Devices for cutting a sheet of dough into pieces and packing the dough pieces into containers are generally known. U.S. Pat. No. 3,427,783 to Reid, discloses one such dough cutting and packing apparatus. Improvements to the Reid apparatus are included in U.S. Pat. No. 5,247,782 to Rejsa.
In Reid, a retaining and releasing assembly is positioned above a center region of a cutting unit. The retaining and releasing assembly includes a plurality of retaining and releasing heads or tubes which are mounted to the cutting and packing apparatus for reciprocating movement through hex-shaped cups or openings in cutting plates carried by chains in the cutting unit. As the tubes move downward, they contact dough pieces retained within the hex-shaped openings in the cutting plates. Vacuum pressure throughout the tubes allows the tubes to retain the dough pieces as the tubes move through the openings in the cutting plates, thereby removing the dough pieces from the cutting unit.
Continued downward movement of the tubes causes the tubes to enter the open ends of containers positioned beneath the cutting unit. Thus, downward movement of the tubes is referred to as the packing stroke. Air expelled from the tubes causes the dough pieces to be deposited in the container. The length of the tubes are graduated so that the dough pieces are deposited in the bottoms of the container at the start of the packing operation and near the tops of the containers at the end of the packing operation until the containers are filled.
The containers are properly positioned for receiving the dough pieces by a plurality of pairs of laterally extending, horizontally disposed upper and lower flighted augers. Empty containers are delivered to a first end of the flighted augers by a first endless belt conveyor. A second endless belt conveyor removes filled containers from a second end of the flighted augers. As the containers move through the augers, the dough pieces are deposited in the containers.
The cutting unit is intermittently driven. An electric drive motor is coupled to a first gear box which in turn is coupled to a second gear box by a first shaft. The second gear box is coupled to the cutting unit through a first mechanical intermittent drive. The first intermittent drive allows the cutting unit to move in a step-wise manner to position successive cutting plates beneath the retaining and releasing assembly. The drive motor is further coupled to a crank through a third gear box. The crank is connected to the retaining and releasing assembly, and moves the tubes in a reciprocating fashion. The reciprocating movement of the tubes is synchronized with the step-wise movement of the cutting unit so that the cutting unit only moves when the tubes are not extending into or through the openings in the cutting plates.
In Rejsa, as in Reid, the dough cutting and packing apparatus includes an endless cutting unit having a plurality of cutting plates supported by carrier chains. The cutting plates have a plurality of dough retaining openings. The cutting unit is configured to receive a sheet of dough that is pressed into the cutting plates by a presser roller. The pitch of the cutting unit varies with the desired size dough product which also requires a specific carrier chain. The presser roller presses dough into cutter plates which divides the dough sheet into pieces which are held within the dough retaining openings in the cutting plates of the cutting unit. These dough pieces are carried to a packing mechanism which includes a plurality of retaining and releasing heads.
Rejsa also teaches improvements over Reid. The retaining and releasing heads or plungers are moved in a reciprocating fashion relative to the cutting unit by way of a microprocessor controlled servo motor. As the retaining and releasing heads move downward (i.e., through the packing stroke), they contact the dough pieces held within the retaining openings in the cutting plates.
Operation of the servo motor during this packing stroke is controlled by the microprocessor in two stages. In the first stage, the servo motor rapidly accelerates the retaining and releasing heads at a rate in excess of the rate of acceleration due to gravity. Acceleration continues until the retaining and releasing heads enter open ends of containers positioned beneath the cutting unit. In the second stage of the packing stroke, the servo motor rapidly decelerates the retaining and releasing heads which discharges the dough pieces from the heads and deposits the dough pieces in the containers. At the end of the second stage of the packing stroke, movement of the retaining and releasing heads ceases and the return stroke of the heads commences.
By providing the packing mechanism with a servo motor controlled by a programmable microprocessor, the dough cutting and packing apparatus can pack containers without the need of a pressure/vacuum blower and accompanying ducts, pipes, manifold assembly and noise as was used in Reid. Rather, the acceleration and deceleration techniques ensure proper packing without the use of air pressure in the retaining and releasing tubes.
In the systems taught by both Reid and Rejsa, each size dough product is based upon a particularly dimensioned hex-shaped cup. Thus, the length of the cutting plates in the cutting unit varies as the size of the product varies. This requires that the index (or distance) that the cutting unit must move for each stroke of the retaining and releasing heads is specific for each different size dough product.
The containers in Rejsa are moved relative to the packing mechanism in a similar manner to that taught by Reid. A container positioning mechanism defined by a plurality of pairs of flighted augers drive the containers such that the containers are intermittently stopped below respective retaining and releasing heads until the packing mechanism completes a packing stroke and transfers dough pieces from the cutting unit to the containers. Each container size is specific for only one size dough product. The can index profile is specific to the number of dough pieces packed per can and the width, or number of biscuits, of the cutter bar. The dough packer index rate is limited by the inertia of the machine and interference conditions of each cycle. Since alignment of the containers with the hex-shaped cup in the cutter bar is essential for the dough piece to be successfully packaged, the screw pitch and spacing of the flighted augers are specific for each dough product.
Further, the cutting plates are carried through the cutting and packing apparatus by chains driven by an indexing drive. The cutting plates are attached to links in the chains. The length and dimensions of the links are specific to a particular size dough product, as the cutting plates have a specific length, which is determined by the size of the biscuit and the number of biscuits in the cutter bar. Each size dough product, therefore, has a unique carrier chain link size and a drive sprocket which accommodates that chain link size.
Therefore, the present dough cutting and packing apparatus is dedicated to cut only one size dough product and to pack those dough pieces into corresponding sized containers. Each size product requires a particular hex cup size, cutting plate, carrier chain and container index screws or augers.